A congruent or 2D structural phase transition is observed, via Monte Carlo simulations, in a Σ = 5/(002) twist boundary that is induced by segregation of Ni from the bulk of a single-phase Pt(Ni) alloy bicrystal. This segregation induced phase transition, at 850 K, is from the coincident site lattice (CSL) structure to the type 2 structure, which involves a change in the space group from p421∲2′ to p42′2′. For bulk concentrations up to 0.6 at. % Ni the boundary has the CSL structure, while for a bulk concentration of 7 at. % Ni the type 2 structure is stable. Evidence is presented for chemical ordering at this interface.
ASJC Scopus subject areas
- Physics and Astronomy(all)